Optoelectronic components that emit light may be, by way of example, light emitting diodes (LEDs) or organic light emitting diodes (OLEDs). An OLED can have an anode and a cathode with an organic functional layer system in between. The organic functional layer system can have one or more emitter layers in which electromagnetic radiation is generated, a charge carrier pair generating layer structure including two or more respective charge carrier pair generating layers (“charge generating layer”, CGL) for charge carrier pair generation, and one or more electron blocking layers, also referred to as hole transport layer(s) (HTL), and one or more hole blocking layers, also referred to as electron transport layer(s) (ETL), in order to direct the flow of current.
Optoelectronic subassemblies have, by way of example, two or more optoelectronic components, for example LEDs and/or OLEDs, and actuating circuits, for example drivers, for operating the optoelectronic components. The optoelectronic components may, by way of example, be electrically connected in electrical parallel. An optoelectronic component, for example an OLED, may be segmented and therefore have multiple OLED elements. The OLED elements may, by way of example, be electrically connected in parallel and/or share at least one common electrode. By way of example, two OLED elements have the same cathode, but have mutually isolated organic functional layer structures and accordingly mutually isolated anodes. This can contribute to a short in one of the OLED elements allowing the other OLED elements to continue to be operated in principle.
Despite complex quality controls for OLEDs, OLEDs in application cannot be prevented completely from failing spontaneously. A typical fault pattern for spontaneous failures are shorts between the electrodes. Such shorts are normally very small in terms of area, and therefore a large part of the total current is concentrated at this short point. The current density is consequently distinctly inflated, which means that these points can heat up to a very great degree depending on formation. This can lead to the electrodes melting, to dark spots in the illuminated image, to completely dark OLEDs and/or simply to points on the OLED that become very hot. In order to prevent potential hazards as a result of this overheating (combustion risk, fire, rupture), such a short should be identified by the actuating or driver electronics or a superordinate evaluation unit and/or computation unit and an appropriate reaction, for example a protective measure, should occur (disconnection of the shorted component, generation of warning signals, bypassing, that is to say circumvention of the short, etc.). Specifically in the automobile sector, it is a requirement for manufacturers that e.g. defective OLEDs or LEDs in rear lamps have to be identified electronically and reported at least to the onboard system.
It is known practice to identify shorts in OLEDs by virtue of an overvoltage or undervoltage across the OLEDs being recorded and being used as a criterion for a defect. As a reaction to the identification of the short, it is possible for bypassing and/or fault signal generation to occur.